boost leak ?

[kjunio14]

my car seems to have a loud hissing sound as i start to build revs, and there is a obvious feel of power loss. but this does not seem to happen all the time, as the car seems to be boosting fine most of the time. i havent got a boost gauge in my car yet, so i cant visibly see anything. i've seen diy boost leak kits and stuff, but im pretty incompetent under the hood. im just wondering what the diagnosis is for a boostleak and is there is a place that can check and fix it for me.

cheers

[Nepharius]

I had this the other day, but I had forgotten to put one of the clamps back on after putting my intercooler back on..... Anyway Id have a look under your bonnet, remove the black shroud and check all the metal clamps are on tight (should be 2 on either side of the intercooler) and that the rubber pipes either end of your intercooler aren't damaged. Basically the only places you can leak boost are these or somewhere around your Blow off /By Pass Valve. (at least thats my understanding)

I think Ive heard somewhere you put soapy water on things and then look for bubbles forming. Maybe someone else can give you some better tips about that though.

[Doc]

just check all your clamps between yout turbo and your throttle body bud.. lets start there

[Crusher_13]

my car seems to have a loud hissing sound as i start to build revs, and there is a obvious feel of power loss. but this does not seem to happen all the time, as the car seems to be boosting fine most of the time. i havent got a boost gauge in my car yet, so i cant visibly see anything. i've seen diy boost leak kits and stuff, but im pretty incompetent under the hood. im just wondering what the diagnosis is for a boostleak and is there is a place that can check and fix it for me.

cheers

What have you done that could cause a boost leak? i.e. what have you put into the car or touched that could cause this?

Most of those clamps are not going to just come loose.

[Jmac]

Im putting a tenner on the pipe between the TMIC and the Turbo, so Id be checking that first.. Ive had that come loose after no recent under-the-bonnet fiddling.
The engine does move around a bit!

[kjunio14]

thanks for the help ,i'll check the clamps and rubber piping around the intercooler properly this weekend with a mate. i havent touched the car, its stock. i've only had it for a few months. i bought it with 120k's on it, but everything is mint condition and working perfectly. this is the only problem that has happened so far. i'll check out the clamps and stuff, and hopefully post up the problem

cheers

[Jmac]

No problemo. Mine was the clamp on the turbo side. The clamp seemed to have been a bit high and slipped off on one side. Should only need a Phillips head and flat head to find where the pipe is in relation to the hose. Be careful not to loosen it too far to drop it down, unless you have smaller hands than me! Also do it in the morning before you have driven... It gets VERY warm back there and it's hard to poke around with gloves on!

[blackbetty]

Welcome to OZMPSclub and congrats on getting a sexy MPS6.

Ditto as others have said, not too long ago I had the exact same problem the loud hissing sound when building revs and no boost. Like you said also it was not all the time then progressively got worse until the car felt like a big black slug and was struggling to even get up the top of Mt Panorama even in third gear, was hideous and embarrassing.

My hose clamp was just sitting there lose around the end of the pipe on the intake side of the Intercooler, eventually it worked itself completely loose and was just sitting hanging down the bottom of the bend in the pipe. The guys on the bathurst cruise found the problem for me and tightened it. Definately check the clamps it could have been sitting there loose on the end of the clamp keeping majority of boost in there and be working itself completely off hence it boosting fine most the time.

[kjunio14]

I just checked the intercooler clamps and everything seems fine. The only visible thing I can see is a small cut on the bpv tubing. The cut is very small and not deep, it's just under the clamp. Could this be a big enough reason for a boost leak ?

[Doug_MPS6]

Doesn't sound good. I'd pull it off and check if it goes right through, if it is not plainly evident in superficial inspection. Check all clamps anyway. BB's story is enough to convince you. These things get loosened at service time to access plugs, etc, and some might have been forgotten when it is all being screwed down again.